Neutralizer bar



Nov. 12, .1929. w, H, CHAPMAN 1,735,494

NEUTRALIZER BAR Filed Feb. 12, 1925 Patented Nov. 12, 1929 UNITED STATESPATENT OFFECE WILLIAM H. CHAPMAN, OF PORTLAND, MAINE, ASSIGNOR TOCHAPMAN ELECTRIC NEUTRALIZER COMPANY, OF PORTLAND, MAINE, A CORPORATIONF MAINE NEUTRALIZER BAR Application filed February 12, 1925. Serial No.8,853.

My invention consists ot a new and improved type of discharge bar forremoving static electricity from the surface of charged paper or otherflat surfaces, as in a printing press.

The object of my invention is to provide a bar with flexible dischargepoints which are suliiciently stilll to retain their erect position inrelation to the bar whatever may be the lo position of the bar withreference to the surface of paper to be treated and yet flexible enoughto yield readily to anything that happens to strike them. Y

I attain my object byconstructing discharge points of line spring wireof steel 0r phosphor bronze wound with a cone shaped end and retained ina suitable cylindrical receptacle and having a metallic connection withthe conductor of the bar.

A bar constructed according to my ini-.feiltion is shown in theaccompanyin drawing in which F ig. 1 is a longitudinal upright section-7Fig. 2 is a cross section on the line QZ of Fig. l, and

Fig. 3 is a section like Figure 2 but showing a modification.

A is an iron pipe, B is a libre insulating sheath or tube inclosing it7and D and D are hard rubber insulating bushings which provide a point ofattachment for a supporting bracket (not shown).

C and C are metal plugs screwed into the end of the pipe. E is a steelterminal point to receive a bayonet socket for connection with atransformer or other source of high tension electricity. An optionalposition for this terminal point is shown by dotted lines at E. A seriesof brass receptacles F are screwed into the pipe A each containing aspring G of line wire formed with a cone shaped end by winding the wireclosely onto a sharp pointed arbor, the winding being inished at thepoint where a short piece off the wire is leftV projecting. The arbor onwhich the spring is wound has a slightly enlarged portion at thestarting point of winding which forms an enlarged portion G and ashoulder on the spring. The receptacle F has an enlarged opening at itsinner end to receive the enlarged portion of the spring and this end isslotted as at A so that after the spring is put into place the end otthe receptacle can be pinched together with suitable pliers so as toretain the spring lirmly in position with its shoulder against theshoulder in the receptacle.

I construct these springs preferably ot No.

25 tinned steel spring wire wound on an arbor which makes the body otthe spring'. 60 1/8 inch outside diameter' with a base portion outsidediameter tapering at the outer end to a point. A spring thus constructedcan be doubled over against the side of the bar without infury as it hassurfiicient elasticity 55 to restore itself to erect position a'fterbending.

In using a bar of the type disclosed it is positioned in a machine withrespect to the traveling paper or fabric and so that its dischargepoints are properly spaced from the traveling material. Accordingly itis important that these points be at and remain at a iiXed distance fromthe axis of the bar, e1- cept as they may temporarilyk yield whenflStruck by the material or an operator. Therefore the spring G is woundclosely with its convolutions in contact with one another to prevent anyyielding of the point in direction away from the material and along its'gq own longitudinal axis which is at right angles to the longitudinalaxis of the bar. lllhen the bar is positioned on the machine and thepoints are properly spaced from the material they Will retain theirinitial relationship 1 therewith since they cannot be compressedlongitudinally and, when bent over laterally, are returned by their ownresiliency to their initial position. This arrangement enables the barsto be used with t ieir points project- "ne ing upward or downward or inany other desired direction and at a predetermined distance `from thesurface ot the material being neutralized, and insures that thisdistance will be maintained.

Discharge bars with rigid points have caused bad wounds in the hands andarms of lo erators accidentali 0'ettino` against them l b 1D as theywork about the machines on which they are placed.

To avoid this some bars have been constructed with the active pointsenclosed in a sheath of rubber or porcelain and having only the extremeend of the point exposed. Others have been constructed with a flexiblemetal tape hanging down from the bar to constitute the active point. Inthe former case the enclosing sheath of insulating inaterial requiresfrequent cleaning as it gets clogged up with lint, inl; or dirt ofvarious kinds and in the latter case the bar cannot be used with theactive points directed upward or horizontally as is required in somekinds of printing presses Where the paper runs vertically or over thedischarge bar. My present bar obviates both of these difficulties andcan be used in any position.

In Fig. 3 I have shown a modification in Which the retaining device 7for holding the point g is constructed of hard rubber instead of metal.By using hard rubber instead of metal the effective length of the pointis increased as the retaining device is a non-conductor instead of aconductor and the current must flow through the entire length of thepoint from the pipe A.

The retaining device or hard rubber receptacle f has a flaring opening fwhich permits the end of the point g to be bent when encountered by anyobject. The inner end g of the point g is enlarged to rest on the end ofthe receptacle f and is pressed firmly against the inner Wall of thepipe A.

I claim l. A discharge bar for neutralizing static electricity having aseries of discharge points, each point consisting of a single Wire Woundhelically With its convolutions in contact and forming a cone-shaped endterminating in a straight section of Wire.

2. A discharge bar for neutralizing static electricity comprising aconducting tube; a series of receptacles secured in said tube along oneside thereof; and a discharge point supported in each receptacle havingelectrical connection with said tube, each point being a Wire helicallyWound With its convoititions in contact With one another to provide ahollen7 body portion With cone shaped end terminating in a straightsection of the Wire and being arranged in said receptacle so as topermit the point to yield laterally but not along its axis toward thereceptacle upon contact with an object and to be returned to its initialposition by its own resiliency.

3. A discharge bar for neutralizing static electricity comprising aconductor; a series of discharge points projecting therefrom along oneside thereof having electrical connections with said conductor; eachsaid point being a helically wound Wire with its inner end fixed inposition and with its convolutions in contact With one another so thatit can not yield toward the receptacle but so

